1. Field of the Invention
The invention relates to a spring device for connecting two flanges in accordance with the preamble of Patent Claim 1.
2. The Prior Art
Spring devices of this type, which are disclosed in DE 41 01 849 A1 and DE-B-1 187 437, are unsuitable for high connection forces. At the same time, the device according to DE 41 01 849 A1 also does not provide a secure hold on the flanges without additional locking means. The device according to DE-B-1 187 437 is comparable, with regard to its structure and action, to a clothes peg operating with a tension spring. The structure thereof is complicated and the clamping forces which can be applied with the tension spring are extremely limited unless an outlay which is no longer economically viable for such parts is made.
DE 44 44 550 A1 discloses a spring device in which the flanges which are to be connected to one another are connected frictionally and in a form-fitting manner to one another between two cup springs which are braced towards each other. At least the end surface on one of the two flanges which are connected to each other and against which one of the two cup springs bears, is of spherical design around its periphery. Moreover, the said flanges can be connected to each other in the manner of a ball-and-socket joint. The flanges are situated in each case at the ends of conduits which are to be connected to one another via the flanges. The said cup-spring connecting device is complicated to fit. Moreover, in conduits which are connected to one another via flanges, the cup springs cannot be removed for replacement from the ends of the conduit in a non-destructive manner if the conduits are fixedly installed, for example in the exhaust system of a motor vehicle. However, the sphere of application corresponds to the that sphere to which the invention refers in terms of generic type. In particular, the connection forces and the angle offset which is possible in that known device and under which the conduits and therefore their flanges can be connected to one another, together with the demands made of a connection according to the invention, are of comparable type and size.
The invention is concerned with the problem of providing a spring device which can be fitted and replaced easily and can be produced cost-effectively and which ensures a secure hold in particular without additional aids.
This problem is solved by a spring device of the generic type having the characterizing features of Patent Claim 5.
A spring device of this type can be pushed on in a simple manner laterally and radially at the end sides of the flanges to be connected to one another, and can therefore also be readily replaced at any time by simply pulling off.
This makes available a spring clip which in the fitted state acts or can act in a clamping manner in different directions. In this arrangement, the clamping action in one direction causes the flanges gripped in the clamp to be pressed against one another, and the clamping action in the other direction causes the conduits, which are preferably cylindrical pipes and which are adjacent to the flanges to be connected and are connected to them, to be unclamped. The spring actions directed in two different directions can differ in size as desired.
The limbs of the clamping jaws have regions which are only locally tightly restricted and in which they bear against the flanges and against the conduits connected to the said flanges. Small contact surfaces of this type permit a secure hold and in the case of hot flanges or conduits connected to the said flanges protect the spring device from a high flow of heat into the spring device. The locally restricted bearing regions have virtually the function of a heat throttle. A slight flow of heat into the spring element prevents excessive heating of the spring element at high temperatures of the parts to be connected by the spring element. Low temperatures at the spring device are important, since with the same spring material the spring force decreases with rising temperatures.
A spring device with the limbs of its clamping jaws acting in a clamping manner in two different directions is a virtual necessity in this form if the clamping-jaw limbs rest in a locally restricted manner on a spherical bearing surface of the flanges, which surface is formed by an annular strip from a spherical surface. In this arrangement, the individual bearing regions of the limbs of a clamping jaw bear on the same peripheral annular strip. If, in the tension state of the spring device, i.e. in a state in which it is pulled up onto the flanges to be connected, the distance between the limbs of the functionally first clamping jaws is changed by a pivoting movement between the two first clamping jaws, then by means of the double clamping action of the spring device on account of the individual limbs bearing on a spherical annular segment, the distance between the U-limbs of the functionally second clamping jaws also changes.
For a statically satisfactory alignment of the spring device on the supports of flanges which are to be connected to one another, in particular of such flanges in which at least one flange support surface is of spherical design, it can be expedient that a different number of bearing regions is provided on in each case one of the functionally first and/or second clamping jaws.
The bearing regions in the clamping jaws are in each case positioned in such a manner that in the push-on direction of the spring device a type of snapping onto the circumference of those parts which are to be connected to one another via the flanges and which are in particular pipes, can take place. This radial snapping-on provides a means of securing against slipping.